The cosmetics industry uses a wide variety of articles made from two or more different colors of plastic to serve as brush handles, applicator handles, lipstick tubes or cases, lip pencil handles, eye pencil handles, cosmetic compact cases, nail implement handles, and the like. Typically, such articles made from acrylics in two or more different colors by a cold pour (or casting) method.
Cold pour is a multi-step method in the prior art, requiring more than one piece of equipment, as illustrated in FIG. 9. First a single-colored acrylic resin is run through a standard injection molding machine to make a pre-determined, specifically-sized, single-color product that is shaped by the use of molds or tools. The shaping method may vary depending upon the requirements of the finished product. Then, a Formica resin, heated to its melting point, is manually poured into a freestanding cast mold, following which the injection molded piece is placed into the liquid Formica in the mold and is secured in place until the liquid Formica cools and sets. Thus, the solidified Formica creates an exterior portion that seals around the inner acrylic core, after which the finished product is removed from the molds.
A disadvantage of the cold pour method is that it cannot be performed using only a single injection molding or extrusion machine, rather it requires a secondary casting tool and additional steps to produce the final multi-colored product. Additionally, the cold pour method requires a tool that has been appropriately sized and shaped to the desired geometry of the finished product. As a result, open chamber (i.e., unlimited length) tools cannot be used. The casting mold determines the exact shape of the finished product. Further, the finished product comprises raw materials that are both acrylic and Formica. The product is not composed entirely of acrylic.
A need, therefore, has existed for an improved method of making a multi-colored acrylic cosmetic brush handle which is less labor intensive and less expensive to produce that presently available.